RESO Web API vs RETS in Canada: What Your Realtor Website Actually Needs in 2026

By Cody Wise, Founder, Wise Media. Published 5 September 2026.

RESO stopped certifying RETS in 2018 and the RESO Web API replaced it, but in Canada the answer is not that simple. CREA’s DDF is not RETS. Toronto’s PropTx runs a RESO API for both IDX and VOW. And Alberta’s Pillar 9 was still shipping a RETS feed as of September 2026. What your realtor website needs depends entirely on which board you pull from.

Summary

• RETS is deprecated, not switched off. RESO discontinued RETS certification in 2018. Each MLS operator decides its own shut-off date, and no Canadian board publishes one.
• The RESO Web API is OData v4 over REST, JSON payloads, OAuth authentication. Current certified versions are Web API Core 2.0.0 and Data Dictionary 2.0.
• Canada is not bound by NAR policy. The rule that forced US MLSs onto the Web API is NAR MLS Policy Statement 7.90. CREA has no published equivalent.
• CREA runs two interfaces. A legacy XML DDF data feed with RETS-style transaction names that is not actually RETS, and a separate OData-based DDF Web API.
• PropTx, TRREB’s subsidiary, is RESO API for IDX and VOW. Both require a signed brokerage agreement.
• Pillar 9 in Alberta was still RETS in September 2026, delivered through Trestle. That single fact undoes most of what gets written about this topic.
• Ask your developer which feed type your board actually ships before you sign anything. It changes the build, the cost and the timeline.

Table of Contents

1. What is RETS and why is it being retired?
2. What is the RESO Web API?
3. RETS vs RESO Web API compared
4. What Canadian realtors actually get: CREA DDF, PropTx and Pillar 9
5. IDX, VOW and DDF are three different things
6. What CREA’s display rules require on your website
7. How to choose a feed for your build
8. Common mistakes
9. Frequently asked questions

What Is RETS and Why Is It Being Retired?

RETS, the Real Estate Transaction Standard, is the data transport protocol the North American MLS industry ran on for two decades. It launched in 1999, back when RESO was still part of the National Association of REALTORS rather than an independent standards organisation.

Its ending was undramatic. At the RESO Spring Summit in Austin in 2017, the RETS Workgroup announced that after more than eighteen years it had completed its final release with RETS 1.9, and the workgroup would be retired because there “is no more business to transact.” Cary Sylvester of Keller Williams put it more usefully at the same event: “RETS is not dead, because it’s not dead until you quit using it. But we are not going to extend it further. We are going to focus on the RESO Web API.” She compared it to Adobe Flash. (RESO, RETS Sunset)

RESO’s own certification page is blunter today: “Some systems still use the Real Estate Transaction Standard (RETS), but this is a deprecated legacy method of data transport that RESO discontinued certifying in 2018.” (RESO Certification)

Read that carefully. RESO stopped certifying RETS. It did not switch anything off, and it has no power to. There is no industry-wide RETS deadline. Every MLS operator sets its own, and a lot of them have not.

What Is the RESO Web API?

The RESO Web API is a REST interface built on the OData v4 specification. You authenticate with OAuth, request resources over HTTPS, and receive JSON. If your developer has ever consumed a modern SaaS API, they already know how it behaves. (RESO Web API)

Two RESO standards matter for a website build:

• Web API Core governs transport. How you query, filter, page and replicate. Currently certified at version 2.0.0.
• The Data Dictionary governs meaning. What a field is called and what values it accepts, so that “Bedrooms” means the same thing in Calgary and Kelowna. Currently certified at version 2.0, with more than 1,700 fields and 3,100 lookups. RESO notes that “adoption of the full Data Dictionary is not expected for most organizations and is not required for certification.” (RESO Data Dictionary)

That last sentence is the one that catches integrators out. A certified feed is not a complete feed. Two boards can both be RESO certified and still hand you materially different field coverage, which is why “it is RESO, it will just work” is a claim to test rather than trust.

Why US MLSs moved and Canadian ones did not have to

The migration in the United States was not organic. NAR MLS Policy Statement 7.90 requires MLS organisations owned and operated by associations of REALTORS to implement the RESO Data Dictionary by 1 January 2016 and the RESO Web API by 30 June 2016, and to keep current by implementing new releases within one year of ratification. (NAR Handbook on Multiple Listing Policy, 7.90)

Canadian boards are not bound by NAR policy. CREA publishes no equivalent mandate that we could find. RESO counts “484 functioning MLS systems in the United States, more than 30 in Canada,” and its transition leaderboard reports progress in US subscriber percentages only. Those figures do not describe Canada, and anyone quoting them at you about a Canadian board is quoting the wrong country.

RETS vs RESO Web API Compared

	RETS	RESO Web API
Foundation	Industry-specific protocol, launched 1999	OData v4, a general web standard
Payload	XML, often compact or COMPACT-DECODED	JSON
Authentication	Digest or basic, session cookie	OAuth 2.0 bearer token
Query syntax	DMQL2, proprietary	OData filters, standard
Developer pool	Shrinking. Specialist knowledge	Any competent REST developer
Field naming	Board-specific unless Data Dictionary mapped	Data Dictionary names by default
Certification	Discontinued by RESO in 2018	Active. Web API Core 2.0.0, Data Dictionary 2.0
Tooling	libRETS and a handful of legacy libraries	Standard HTTP clients and OData libraries

The practical difference for a website owner is cost of change. On a Web API feed, adding a field or a new search filter is a query change. On a RETS feed, it is often a mapping exercise against board-specific field names that only one person on the project understands. That gap compounds over the life of a site.

What Canadian Realtors Actually Get

Here is where every article written from a US desk stops being useful.

CREA’s DDF is not RETS, and it is not one thing

The Data Distribution Facility is CREA’s permission-based syndication system. Its current policy document, revised June 2026, describes six distribution channels: National Shared Pool, National Franchisor Pool, Franchisor Direct Feed, Member Website Feed, Real Estate Advertising Websites and Partner Websites. Participation in four of those is mandatory for boards and associations, while brokerage and salesperson participation is opt-in through the DDF dashboard. (CREA DDF Policy and Rules, June 2026)

CREA operates two technically distinct interfaces:

• The legacy DDF data feed. It uses RETS-style transaction names, Login, Metadata, Search, GetObject and Logout, and a DMQL2-flavoured query syntax, which is why so many developers call it RETS. It is not. CREA’s own FAQ gives the game away: “Common RETS clients, such as libRETS, may not support Standard-XML format for search results, which is the only format available from CREA’s DDF Data Feed.” A RETS client cannot reliably read it. (CREA DDF FAQ)
• The REALTOR.ca DDF Web API. Documented separately and linked from CREA’s own pages, this is an OData interface with resources named Property, Member, Office and OpenHouse plus replication endpoints, authenticated with an OAuth client-credentials bearer token.

One honest caveat, and it matters because vendors blur it. CREA does not publicly claim RESO certification for the DDF Web API on any page we could reach. The accurate statement is that CREA publishes an OData-based Web API alongside the legacy XML feed. If a vendor tells you CREA is RESO certified, ask them to show you where CREA says so.

Three legacy DDF quirks worth knowing before you scope a build. There is no ad-hoc querying, because clients are expected to pull all listings available to them and filter locally. Filters are configured in the DDF dashboard rather than at runtime. And photo streaming through GetObject was discontinued on 6 July 2020, so images now arrive as URLs.

Toronto and PropTx: RESO API for both IDX and VOW

PropTx Innovations, TRREB’s wholly owned subsidiary, now describes both of its data products in RESO terms. On IDX: “Internet Data Exchange is now being offered in RESO API format. PropTx RESO API IDX provides all Brokerages that have completed the Internet Data Exchange (IDX) Data Agreement access to the available listings data for all opted-in Brokerages via the API.” (TRREB IDX Data Feed)

On VOW: “PropTX is offering access to the VOW Datafeed in a RESO API format,” with an agreement requirement and the ability to designate an Affiliated VOW Partner. Both agreements are signed through the PropTx Data Syndication and Agreement System. (TRREB VOW Data Feed)

What TRREB does not publish is a RETS decommission date. Treat the RESO API as the way in, and do not build a plan around a shut-off date nobody has announced.

Alberta and Pillar 9: still RETS

Pillar 9, the registered operating name of Alberta One Realty Listing Services, is the MLS system behind most Alberta boards including Calgary. As of a check on 5 September 2026, IDX Broker’s public Pillar 9 coverage page lists the feed type as RETS, delivered through Trestle, with a data management fee of $10.00 monthly and a data connection fee of $35.00. The vendor slug on that page is literally “p9rets.” (IDX Broker, Pillar 9 coverage)

That single line is the reason this article exists. If you are a Calgary or Edmonton agent reading an American blog post announcing that RETS is dead, you are reading about a protocol your own board may still be handing you. Pillar 9 publishes no public developer documentation and no RETS sunset date, so the only reliable answer is the one your data vendor gives you in writing.

British Columbia

Mixed, and moving. IDX Broker’s British Columbia REALTORS BCCAMLS listing, covering Greater Vancouver, Fraser Valley, Chilliwack and BC Northern, reports feed type WEBAPI through Bridge, with a data management fee of $8.00 monthly and a connection fee of $35.00. The Association of Interior REALTORS, covering the Okanagan and Kootenays, appears on RESO’s own leaderboard of organisations that have completed a 100 percent Web API transition. (RESO Web API Transition Leaderboard)

Source	Feed type	Sold data	Notes
CREA DDF, legacy	XML over a RETS-style interface	No	IDX only. Standard-XML, no ad-hoc queries
CREA DDF Web API	OData	No	Credentials issued per approved Destination
PropTx, Toronto	RESO API	VOW available	Brokerage agreement required for each
Pillar 9, Alberta	RETS via Trestle, as at 5 Sep 2026	Not offered by IDX Broker	No public sunset date
BC, BCCAMLS	WEBAPI via Bridge	Not offered by IDX Broker	Covers GVR, FVREB, Chilliwack, BC Northern

Verify the feed type for your own board before you scope, because these change and the vendor pages are the only public record.

IDX, VOW and DDF Are Three Different Things

Feed type is the transport question. What you are allowed to display is a separate question, and it is the one that actually decides what your website can do.

• IDX shows active listings publicly, no login required. This is what most realtor sites run.
• VOW, a Virtual Office Website, shows more, typically including sold data, behind a registration and a broker-client relationship. In Canada it is available through some boards and not others.
• DDF is CREA’s national syndication facility. Broad national coverage, IDX-style display, and consistently no sold data.

One limitation catches a lot of Canadian agents by surprise. IDX Broker states plainly that it “does not currently support Sold Listing data or Virtual Office Website (VOW) services for real estate systems in Canada. This includes, but is not limited to, systems operated by the Canadian Real Estate Association (CREA), the Toronto Regional Real Estate Board (TRREB), and other Canadian real estate boards and associations.” (IDX Broker, fees explained)

If sold comparables are the centre of your value proposition, that constraint decides your vendor before anything else does. Build the funnel around what you can legally show. A home valuation landing page and a strong lead-converting realtor site can carry a lot of weight without sold data on the page.

What CREA’s Display Rules Require on Your Website

If you pull DDF, the display obligations are contractual and specific. From the June 2026 policy document, listing content must clearly and prominently:

• Display the Powered by REALTOR.ca logo, linked directly to that listing on REALTOR.ca, at a minimum of 90 pixels wide in a 1:1 ratio.
• Display the listing brokerage name plus whatever provincial law requires, legible without clicking.
• Display CREA’s photo watermarks without alteration or obstruction.
• Disclose any AI, augmented reality or virtual staging and distinguish it from original content.
• Carry an MLS and REALTOR trademark statement on every page.

Operationally, the same rules require a refresh at least once every 24 hours with removal of anything no longer current, integration with CREA’s Analytics Web Service API to report listing activity, and a cap of ten websites per participant. Filtering is permitted only on objective criteria: geography, list price, rentals, property type and property features.

One clause is newer and worth quoting in full, because it will shape the next few years of real estate data: “Nothing in these Rules provides any person the right to use Listing Content for the purpose of training artificial intelligence systems.” Participants are also required to take reasonable precautions against scraping, including monitoring and blocking.

Enforcement gives ten business days to remediate after a request, with suspension available during that window and immediate suspension available for any violation. On termination you must stop displaying the content and destroy all local copies.

Trademark use on the site itself is a separate rulebook again, and it trips up more Canadian agents than the feed does. We covered it in can I use MLS in my real estate website name.

How to Choose a Feed for Your Build

1. Ask your board what it ships, in writing. Feed type, standard version, and whether sold data is available to you. Do not accept a vendor’s summary as the answer.
2. Decide IDX, VOW or DDF based on what you need to display, not on which is easiest to get. National DDF coverage and local board IDX solve different problems.
3. Sign the agreements early. Board data agreements, broker authorisation and, for DDF, the brokerage opt-in have to exist before a vendor can request credentials. This is usually the longest pole.
4. Do not share your credentials. CREA’s rules are explicit: participants may not share or disclose DDF credentials to a technology provider or any other party. Feeds are provisioned to the provider properly, through CREA, not by emailing a password.
5. Budget the data fee separately from the website. RealtyNinja publishes $9.00 CAD monthly or $108.00 CAD yearly for DDF boards and $5.00 CAD monthly or $60.00 CAD yearly for Pillar 9 boards, with no data fee on several direct board feeds. Showcase IDX publishes a $10.00 monthly share of the CREA fee. Verify current rates against each vendor’s own page.
6. Plan for a two to three week provisioning window at minimum. IDX Broker states that “once we receive credentials from the Board MLS System, a new dataset can be live in IDX Broker within 2-3 weeks.” No Canadian board publishes its own approval turnaround.
7. Write the display rules into the build, not into a launch checklist. The REALTOR.ca badge, the brokerage attribution and the 24-hour refresh are structural, not decorative.

Costs beyond the feed are covered in our MLS and IDX integration cost guide for Canadian WordPress sites, which breaks down where the money actually goes on a realtor build.

Common Mistakes

• Assuming RETS is switched off. It is deprecated, not decommissioned, and Alberta is the live counterexample.
• Reading US transition statistics as Canadian ones. RESO’s leaderboard percentages are US subscribers.
• Calling CREA’s legacy DDF feed “RETS.” It looks like RETS and standard RETS clients cannot reliably parse it.
• Promising sold data before checking. Most Canadian IDX vendors do not offer it, and no amount of development changes that.
• Scoping the build before the agreements are signed. Credentials gate everything downstream.
• Sharing feed credentials with a developer. CREA’s rules prohibit it outright.
• Treating display rules as a launch-day task. The badge, the attribution and the refresh cycle are architecture.
• Building a site so dependent on the feed that it ranks for nothing. Listing pages age out. The pages that compound are the ones you write.

Frequently Asked Questions

Is RETS dead in 2026?

Not in Canada. RESO discontinued RETS certification in 2018 and retired the RETS workgroup after the final 1.9 release, but RESO does not operate any MLS and cannot turn a feed off. Alberta’s Pillar 9 was still listed as a RETS feed through Trestle in September 2026. Ask your own board rather than assuming.

Is CREA’s DDF a RESO Web API?

CREA publishes an OData-based DDF Web API alongside its older XML data feed, and the API’s resource names follow RESO Data Dictionary conventions. CREA does not publicly claim RESO certification for it on any page we could find, so the safe description is OData-based rather than RESO certified.

Can I get sold data on a Canadian realtor website?

Sometimes, through a VOW arrangement with a board that offers one, such as PropTx in Toronto, and it requires a signed VOW data agreement and a registration gate on your site. CREA’s DDF does not carry sold data, and IDX Broker states it does not support sold or VOW services for Canadian systems at all. Confirm with your specific board and vendor before you promise it to clients.

What is the difference between IDX and DDF?

IDX is a board-level reciprocity programme letting you display other brokerages’ active listings from that board. DDF is CREA’s national syndication facility, which gives broader geographic coverage under CREA’s own rules and display requirements. Many Canadian sites run one, some run both, and the choice is usually about whether your buyers search locally or across provinces.

How long does it take to get an MLS feed connected?

The technical integration is the short part. IDX Broker publishes 2 to 3 weeks from receiving board credentials to a live dataset. Getting to credentials is the variable: brokerage opt-in, a signed data agreement and board approval. Plan four to eight weeks end to end and start the paperwork before the design is finished.

Do I have to display the Powered by REALTOR.ca badge?

If you display DDF listing content, yes. CREA’s June 2026 rules require it to be clear and prominent, linked directly to that listing on REALTOR.ca, at a minimum of 90 pixels wide in a 1:1 ratio, alongside the listing brokerage name and unaltered photo watermarks.

The Bottom Line

The RESO Web API is where the industry is going and it is the better thing to build on. But “RETS is dead” is an American sentence, and repeating it in Canada leads agents to scope builds against a feed their board does not offer and to skip questions their board can actually answer. The useful question is not which standard won. It is which feed your board ships this quarter, what it will let you display, and what the agreements say.

We build Canadian real estate sites around that answer rather than around a plugin’s marketing page. If you want the feed question settled before design starts, see our website packages or our growth packages for the content side that keeps ranking after the listings turn over, then tell us about your build on the intake form.

Feed types, fees and standard versions change. Every figure here was checked against the linked source on 5 September 2026. Verify against your own board and vendor before committing to a build.

Sources

• RESO, RETS Sunset
• RESO Certification
• RESO Web API
• RESO Data Dictionary
• NAR MLS Policy Statement 7.90
• CREA DDF Policy and Rules, June 2026
• CREA DDF FAQ
• TRREB IDX Data Feed
• TRREB VOW Data Feed
• IDX Broker, Pillar 9 coverage
• RealtyNinja MLS coverage and data fees